The present invention relates to an improvement of a bag for containing therein food which has to be stored under good conditions, For instance grains such as rice grains, and other pulverulent or granular foods liable to generate fluid such as gases during storage in the bag, and being able to discharge only Fluid such as excessive air From the bag and to prevent the outside air From entering into the bag.
In order to improve storge and minimize the bulkiness of the contained foods, there have been developed and proposed in the past varions kinds of food containing bags having a check valve and in which fluid such as air in the bag is discharged for lowering the pressure in the bag to a reduced pressure. The subject of such development, however, was directed solely to bag body and the function of the check valve was to simply discharge the fluid residing in the bag outside and to prevent outside air from entering into the bag.
Though it was possible, with such conventional food containing bags having a check valve, to discharge the fluid residing in the bag outside and to prevent outside air from entering into the bag by means of said check valve, there was a problem that it was unavoidable that a part of the contained food escapes out through a flow path in the check valve when inside fluid in discharged. This possiblity of escape of the food is remarkable when the food is pulverulent or granular.